Blowing device



W. A. SMITH BLOWING DEVICE July 23, 1929.

Filed Aug. 26,. 1926 JIDY/fom INVENTOR. mlffi HAS A1163;

Patented July 23, 1929.

UNITED STATES r 1,721,674 PATENT OFFICE.

WILLIAM A. SMITH, OF SAYRE, PENNSYLVANIA, ASSIGNOR T INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, CORPORATION OF NEW JERSEY.

BLOWING DEVICE.

Application filed August 26, 1926.

This invention relates to rock drills, but more particularly to a blowing device for fluid actuated rock drills of the hammer type.

The objects of the invention are to permit an uninterrupted flow of pressure fluid under full line pressure through the drill and the drill steel for blowing the cuttings from the drill hole and to prevent reciprocation of the distributing valve and the piston during the blowing period.

Other objects will appear hereinafter.

A preferred form of the invention is illustrated in the accompanying drawings, in which Figure 1 is a sectional elevation of so much of a rock drill as will serve to illustrate the invention,

Figure 2 is a view similar to Figure 1 showing the distributing valve and the hammer piston in the positions which they occupy during the blowing period, and

Figure 3 is an end elevation of a portion of the rock drill.

Referring to the drawings, the invention is shown embodied in a rock drill having a cylinder A provided with a reciprocatory hammer piston B. The front end of the piston B is in this instance reduced to form an extension C slidable in a bore D of the cylinder and has a plurality of flutes E near its forward end. I A hollow drill steel F is supported by the front end of the cylinder A and has a shank G against which the blows of the hammer piston are delivered. A suitable closure for the rearward end of the cylinder A is in this instance provided by a head H which may be secured to the cylinder in any suitable manner.

A valve chest J preferably arranged longitudinally of the cylinder A has a valve chamber K in which isarranged a spool type distributing valve L. The type of valve here illustrated is likethat described in U. S. Patent No. 1,589,255, entitled Rock drill spool valve, granted to IV. A. Smith, June 15, 1926. However, the invention is not limited in its use to any particular type of valve. The valve illustrated has a central head 0 which controls a central inlet port P and has end heads Q, and R for controlling the main exhaust ports S and T respectively formed on opposite sides of the inlet port P. The endsof the chamber K are closed by plugs U which also serve as stops for limiting the travel of the valve L.

Serial No. 131,732.

Motive fluid for actuating the piston B is supplied to the rear and front ends of the cylinder through supply passages V and IV respectively communicating with the valve chamber K on opposite sides of the inlet port P. Suitable valve controlling kicker ports X and Y connect the ends of the chamber K with the cylinder A and are controlled by the piston B As shown in this instance, these kicker ports X and Y are crossed for the best operation of the valve and supplemental leak ports Z and 5 preferably connect the kicker ports X and Y with the exhaust ports T and S for the purpose of permitting leakage from the ends of the valve chamber to the atmosphere.

In accordance with the present invention, a bore 0 is formed through the valve chest J to receive a rotatable plug cl having a longitudinal passage 6 and ports and g which are adapted to register with ducts h and leading from the bore 0 to the inlet port P and to the front end of the chamber K respectively. The plug (Z is preferably of sufficient length to permit its forward end 0 to protrude slightly from the bore 0 for the reception of a Washer 79 which may be held against displacement by upsetting the end 0 of the plug. In this way the plug d is held against longitudinal movement in a rearwardly direction.

At the opposite end of the plug '(l is formed a head 1 provided with a lever 1" whereby the plug (Z may be manipulated. The head 9 is preferably formed eccentrically with respect to the plug (l and is adapted to bear with an inner face 8 against the valve chest J for preventing endwise movementof the plug d in a forwardly direction.

An arcuate recess t is formed on the inner face 8 of the plug (Z and the end faces a and o of this recess are adapted to cooperate with a spring pressed plunger 10 slidable in the Valve chest J for limiting rotation of the plug tl. In addition to serving as a stop for the plug (Z, the plunger w is also adapted to cooperate with depresssions :v and y in the head 9 for holding the plug d in its limiting positions.

In the operation of the device, with the parts in the position indicated in Figure 1, pressure fluid for reciprocating the piston B is distributed to the opposite ends of the cylinder A in the usual manner by the valve L. During the normal operation of the drill ward plug U.

some leakage may occur between the piston extension H and the adjacent parts of the drill. Such leakage, however, is insufficient to properly cleanse the drill hole. If, after a certain period of drilling, it be desired to more thoroughly cleanse the drill hole, the plug (Z may be rotated from the position illustrated in Figure 1 to that illustrated in Figure 2. In this position of the plug the ports f and g are moved into registration with the ducts h and 7c and pressure fluid under full line pressure then flows through these channels and through the passage 0 in the plug (Z to the front end of the chamber K to hold the valve against the rear- By thus holding the valve rearwardly and immovable a constant supply of pressure fluid will flow from the inlet port l to the front end of the cylinder for holding the piston B in its rearward limiting position. IVith the piston in this position, the flutes E are partly withdrawn from the bore D and pressure fluid under full line pressure passes through the flutes, the bore D and through the drill steel F to blow the cuttings from the drill hole. After the drill hole has been thoroughly cleansed, the hollow plug (Z may be rotated to the positon shown in Figure 1 and the valve and the piston will again function in their normal manner.

I claim:

1. In a rock drill, a cylinder, a piston in the cylinder, an extension on the piston having a passage therein, a valve chest having a chamber and an inlet port, supply passages leading from the chamber to the cylinder on opposite sides of the piston, a valve in the chamber controlling the distribution of pressure fluid to the supply passages, kicker passages leading from the valve chamber to the cylinder on opposite sides of center thereof to control the movement of the valve, a bore in the valve chest, ducts leading from one end of the chamber and from the inlet port to the bore, a manually operable plug in the bore, said plug having a passage and ports communicating with the ducts to establish direct communication between the inlet port and the cylinder at the front end thereof and-through the passage to a drill steel.

2. In a rock drill, a cylinder, a piston in the cylinder, an extension on the piston having a passage therein, a valve chest having a chamber, an inlet port in the valve chest in constant communication with the chamber, supply passages leading from the chamber to the ends of the cylinder, a valve in the chamber controlling the distribution of pressure fluid from the inlet port to the supply passages, a bore in the valve chest, ducts leading from one end of the chamber and from the inlet port to the bore, crossed kicker ports leading directly from the valve chamber to to the cylinder on the opposite sides of the center thereof, a manually operable plug in the bore having a passage therein to establish direct communication between the ducts independent of the kicker ports for conveying pressure fluid substantially under full line pressure from the inlet port to the end of the chamber to hold the valve immovable in the opposite end of the chamber, and permitting an interrupted flow of pressure fluid from the chamber into one end of the cylinder and through the passage in the ex tension to a drill steel.

In testimony whereof I have signed this specification.

IVILLIAM A. SMITH.

CERTIFICATE OF CORRECTION.

Patent No. 1,721,674. Granted July 23, 1929, to

WILLIAM A. SMITH.

It is hereby certified that errcr appears in the printed specification of the above numbered patent requiring correction as fellows: Page 2, line 75, claim 2, for the word "interrupted" rearl "uninterrupted"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent ()fiice.

Signed and sealed this 20th day of August, A. D. 1929.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

